When your air conditioner starts emitting weird or unappealing smells, it is necessary to take notice because it could be a sign of a big problem. Ignoring unpleasant smells coming from your air conditioner could lead to further damage to your HVAC system or even pose a risk to your health and safety.

Depending on the smell, the cause may be bacteria or fungus in the system. Other times, it could also sign something mechanically wrong with the air conditioner. Some smells are a warning of an unsafe situation, like a natural gas leak.

At Van Haaften Plumbing & Heating, we have a nose for these sorts of things. If you smell something odd coming from your air conditioner, you can bet that our team of talented specialists has smelled it, too—and fixed it! We’ve earned a reputation as the first call for air conditioning repair in Pella.

What does a certain smell billowing out of your air conditioning mean? Here are a few frequent air conditioner aromas and what they might mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it might be caused by a buildup of bacteria or fungus in the unit. When moisture accumulates inside the unit, it can produce an environment that is conducive to the spread of bacteria and fungus. This can produce a nasty odor that is often described as smelling like feet.

Another likely explanation for an odor of stinky feet may be a dirty air filter. When your HVAC system's air filter becomes choked with dirt, dust and other contaminants, it can cause poor air quality and a musty smell that it similar to the smell of feet.

To solve this dilemma, it's important to have a professional inspect and clean your air conditioning system, including the evaporator coil, drain pan and condensate drain line. It's also important to change the air filter on a regular basis to ensure good air quality and protect against the growth of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioner smells like rotten eggs, it might be due to a natural gas leak in the unit or in the surrounding area. Natural gas has a distinct odor, often described as smelling like rotten eggs or sulfur, which is added to it to make it easily detectable.

A natural gas leak is extremely dangerous and requires immediate attention. If you suspect a gas leak, turn off your air conditioning system, immediately open windows and doors to allow gas to escape the area, make everyone leave the building and call your gas company or emergency services immediately.

My Air Conditioner Smells Like Mildew

If your cooling system smells like mildew, it could be due to a buildup of moisture inside the unit. When moisture accumulates inside an air conditioner, it can foster the growth of mold and mildew. This can cause a musty odor that resembles mildew.

Another possible cause of the smell may be a soiled air filter. Once the air filter becomes clogged, it can cause poor air quality and a musty smell that has a resemblance to mildew.

Routine air conditioning maintenance from Van Haaften Plumbing & Heating can help protect against both of these problems, because a good cleaning, inspection and filter change is a terrific way to keep your system working at its best!

My Air Conditioner Smells Like Urine

One of the most distressing situations is when the air coming out of your HVAC system smells like urine.

If your air conditioning reeks of urine, it could be traced back to a number of things. One likely cause is a collection of bacteria or mold in the air conditioning system. This can happen if moisture accumulates in the system and creates a damp environment that can promote bacterial growth. The bacteria can emit a foul odor that some people describe as smelling like urine.

Another possible cause of the stink could be a clogged drain line. The condensation that forms inside the air conditioning unit needs to drain away correctly, but if the drain line becomes stopped up by debris, it can cause water to back up and accumulate inside the unit. This can create a musty smell that resembles urine.

My Air Conditioner Smells Like Burning Plastic

If your AC smells like burning plastic, a possible cause could be an electrical issue with the unit. After a while, the electrical components in the air conditioning system can wear out or break, which can create a burning smell that resembles plastic.

Another possible root cause of the smell could be a foreign object that somehow got in the unit. If something foreign gets caught in the air conditioning system, it can heat up and emit a smell that reminds people of burning plastic.

If you notice something that smells like burning plastic coming from your air conditioner, it’s essential to contact a professional right away.

My Air Conditioner Smells Like Gas

If your air conditioner smells like gas, there could be a natural gas leak in the unit or in your home. Natural gas has a distinctive smell, often described as smelling similar to rotten eggs or sulfur. That’s because an odor is incorporated into natural gas so that it is easily detectable.

As we said earlier, a natural gas leak can be VERY harmful and calls for immediate attention. Should you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, leave the building and call your gas company or emergency services as soon as possible.

Why My Air Conditioner Smells Like Fish

When your air conditioning equipment smell like fish, it could be due to a build-up of bacteria or mold in the unit. Moisture produces an environment that is conducive to the growth of bacteria and mold. This can cause a disgusting odor that is sometimes described as smelling like fish or, as mentioned earlier, it also can result in a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material stuck within the air conditioning system. This often is possible if an animal such as a mouse or bird becomes trapped inside the unit and dies.

To fix the issue, it's important to have a professional inspect and clean your air conditioning system. They can find the source of the smell and take the correct steps to remove any contaminants and stop the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be several reasons a home's air conditioning system smells like vinegar. One possible cause is a dirty air filter. Another likely cause of the smell could be a refrigerant leak. If the refrigerant leaks, it can generate a chemical odor that is similar to vinegar.

To fix the issue, it's beneficial to have a skilled specialist inspect and clean your air conditioning.  If the odor lingers after the cleaning and replacing of the air filter, it's best to reach back out to a professional to identify and repair any underlying issues with your air conditioning. Or, the tech can tell you if your air conditioning needs to be replaced.

If you are planning to upgrade, Van Haaften Plumbing & Heating can help select the ideal unit to fit your home’s needs. We offer reliable, expert air conditioner installation in Pella.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning equipment, it could be due to a refrigerant leak. When the refrigerant leaks, it can create a chemical scent that some people describe as smelling like chemicals or paint thinner, vinegar or acetone.

One other possible cause of the smell could be a problem with the electrical wiring or parts inside the air conditioning system. This can produce a burning smell that resembles chemicals or burning plastic.

If you believe there is a refrigerant leak or an electrical concern, it's important to shut down your air conditioning system immediately and contact a professional to inspect and repair the unit. Refrigerant leaks can be hazardous and may require immediate attention to prevent injury or damage to your residence.

Strange Smell Coming from Your AC? Call the Pros at Van Haaften Plumbing & Heating

If your air conditioner reeks and you aren’t able to fix it simply on your own, reach out to the cooling specialists at Van Haaften Plumbing & Heating. We have years of experience working with a wide variety of air conditioning systems. Our crew has fixed many air conditioning problems over the years—including weird smells. Call us today for quality AC repair in Pella!